Natural regeneration of Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) in forest stands of Hurky Training Forest District, Higher Forestry School and Secondary Forestry School in Pisek

Abstract

Possibilities are assessed of the natural regeneration of Douglas fir under conditions of Hůrky Training Forest District, Higher Forestry School and Secondary Forestry School in Písek, in stand 12C7, forest type 3K5. The stand is situated at an altitude of 430 m above sea level in an area with mean annual temperature 7.3-7.5&degC and mean annual total precipitation 550-575 mm. Under the stand dominated by Douglas fir (65 years of age), natural regeneration of the mean density of 53,800 seedlings/ha appeared due to lateral light coming from the north. The highest density of Douglas fir natural regeneration was noticed under the stand 10-14 m from the stand margin. The light penetrating through the marginal stand wall was found to be of greater effect on the density of natural regeneration than the upper shading caused by the parent stand. With this method of regeneration, Douglas fir is less light-demanding than spruce. Height and height increment of advance regeneration were greater in places with sufficient light near the stand margin. Thus, natural regeneration of Douglas fir is successful there giving conditions for the origin of a new generation of the stand with a sufficient proportion of Douglas fir.